if 5>2:
   print("5 is greater than 2")
   print("222222")
else:
   print("5 is not greater than 2")



age=30
if age<18:
        print("You are underaged")
elif age>=18 and age<=30:
        print("You are young")
elif age>=30 and age<=50:
        print("You are middle-aged")
else:
        print("You are old")

     #判断闰年
year=int(input("请输入年份："))
if year%4==0 and year%100!=0 or year%400==0:
            print("%d是闰年"%year)
else:
            print("%d不是闰年"%year)


 #a,b,c比较大小
            a=int(input("请输入a："))
            b=int(input("请输入b："))
            c=int(input("请输入c："))
            if a>b and a>c:
                print("%d是最大的数"%a)
            elif b>a and b>c:
                print("%d是最大的数"%b)
            else:
                print("%d是最大的数"%c)

num1=float(input("enter num1:"))
num2=float(input("enter num2:"))
op=input("enter op:")
if op=="+":
    print(num1+num2)
elif op=="-":
    print(num1-num2)
elif op=="*":
    print(num1*num2)
elif op=="/":
    print(num1/num2)
else:
    print("输入错误")

